Multi-Protocol Label Switching (MPLS) and Generalised Multi-Protocol Label Switching (GMPLS) are known connection-oriented technologies in which label switched paths (LSP) are established across a network. At each network node along the label switched path a Label Switching Router (LSR) makes a forwarding decision by a simple inspection of a label carried within the header of a received transport unit (e.g. packet).
Label-switched paths can be created by a Network Management System (NMS). The NMS directly instructs each node along a path to implement a required forwarding behaviour. This is the management plane and LSPs created in this way are called Permanent Connections (PC). Label-switched paths can also be created by end-to-end network signalling in an automatic manner. This is the Control Plane and LSPs created in this way are called Soft Permanent Connections (SPC). Both kinds of connections (PC, SPC) can independently coexist within the same network.
An IETF draft “RSVP-TE signalling Extension for the Conversion Between Permanent Connections and Soft Permanent Connections in a GMPLS Enabled Transport Network”, 28 Oct. 2008, describes a process which allows the transfer of ownership of LSPs. That is, a LSP created by the management plane (MP) can be transferred to the Control Plane (CP), or vice versa. Ideally, the transfer of ownership (also called “adoption” or “handover”) should be performed without affecting Data Plane traffic being carried over the LSP.
The draft specified above gives an overview of signalling to perform the transfer of ownership, and suggests modifying the existing Resource Reservation Protocol-Traffic Engineering (RSVP-TE) message to carry an additional flag indicating that ownership is being transferred.